Valve mechanism for hydraulic elevators.



No 786.654. PATENTED APR. 4, 1905. T. LARSSON. VALVE MECHANISM FORHYDRAULIC ELEVATORS.

APPLICATION FILED JULY 29. 1904.

2 SHEETSSHEBT 1.

'WWTH (55555 5 5*: M mi 6 4.

PATENTED APR. 4, 190

T. LARSSON. VALVE MECHANISM FOR HYDRAULIC ELEVATORS.

APPLICATION FILED JULY 29, 190-1.

2 SHEETS-SHEET 2.

UNITED STATES THURE LARSSON,

Patented April 4, 1905.

PATENT OFFICE.

STANDARD PLUNGER ELEVATOR COMPANY, OF WORCESTER, MASSA- CHUSETTS, ACORPORATION OF NEW JERSEY.

VALVE WIECHANlSIVI FOR HYDRAULiC ELEVATORS.

SPECIFICATION forming part of Lette s la e o. 786,654, dated April 4,1905.

Application filed July 29, 1904. Serial No. 218,659.

To all whom it may concern.-

Be it known that 1, THURE LARSSON, a subect of the Klng of Sweden andNorway, residing at Worcester, in the county of Worcester and State ofMassachusetts, have invented a new and useful Valve Mechanism forHydraulic Elevators, of which the following is a specification.

The object of this invention is to improve 10 the valve mechanism used.to control hydraulic and other elevators.

In the drawings, Figure 1 is a perspective view of a plunger hydraulicelevator equipped with the improvements. Fig. 2 is a sectional elevationthrough the valves; and Fig. 3 is a view, on an enlarged scale, of oneof the bushings used in the pilot-valve.

In detail, A designates the plunger; B, the cylinder, and O the car,which may have the usual counterweights 1V attached thereto by ropestrained over sheaves 9.

1O designates a double standing controllingrope, the ends of which aretrained over sheaves 11 at the top of the well and connected to weight12. The two strands of the rope pass downward, are crossed between thepulleys 13, arranged on a lever 14, carried by the car, and then passdown around sheaves 15 at the bottom of the well. One strand of saidrope is connected to the operating-lever 16.

. A shaft is carried forward on the bottom of the car from the lever letand has a handle 17 extending into the car. This forms a means ofordinary construction for controlling the operating-lever from the car.

The valve mechanism consists of a main valve M and a pilot-valve P. Adouble automatic or shut-off valve S is also used. A pressure-pipe 18and an exhaust-pipe 19 are connectcd to the main valve M, which latterconnects to the shut-ofi' valve by two connectingpipes 20 and 21. Theshut-off valves connect by pipe 22 to cylinder B. On the main-valve stemare arranged a piston 23, a valve 2t, controlling the supply, anintermediate piston 25,

a valve 26, controlling the exhaust, and a piston 27, so that when themain valve is moved to the left pressure will flow in through pipe 18,connection 20, and pipe 22 to the elevator-cylinder and so that when thevalve is moved to 5 the right cylinder B will exhaust through pipe 22,connection 21, and pipe 19. The piston 23 is larger than the otherpistons and valves.

The left-hand end of the main valve is connected by a to-and-fro pipe 28to the pilotvalve at two points. The pressure-pipe 18 is connected tothe pilot-valve by a pipe 29 and the exhaust-pipe 19 is connected to thepilotvalve by a pipe 30.

The pilot-valve is made up of valves 31 and 32, an intermediate piston33, and valves 3% and 35, valves 32 and 34 being used as an additionalmeans to prevent leakage when the pilot-'valveis in central position.These parts are arranged so that when the pilot-valve is lowered valves3% and 35 are opened to connect the lower branch of the to-and-t'ro pipe28 to the exhaust-pipe 30, and hence to relieve the pressure at the leftof the piston 23 to cause the main valve to move to the left and so thatwhen the pilot-valve is raised valves 31 and 32 are opened toallow'connection between the upper branch of the to-andfro pipe 28 andthe pressure-pipe 29 to admit pressure on said piston 23 and to causethe main valve to move to the right. The pilotvalves' 31 and 35 work inbushings 200, which have holes 201 bored through the same, so that theflow is graduated corresponding to the opening movement of thepilot-valve in either direction and so that as the pilot-valve returnsto central position the flow to or from pipe 28 is gradually cut oil,which will easily stop the movement of the main valve either in openingor closing. The operating-lever 5 16 is connected to a nut 36, whichengages screw 37 on the end of a rod 38, fitted to slide and turn in thecasing. The end of the rod 38 is connected by an arm 39 to the stem ofthe pilot-valve. Said rod also carries a widec faced pinion 40, engagingwhich is a rack &1, extending from the main-valve stem. These parts arearranged so that when the pilot-valve is moved down to cause the mamvalve to move to the left said rack 41. will turn said pinion 40 andwill cause the screw 37 to run into the nut 36, and thus to move andrestore the pilot-valve to its central or normal position, and so thatwhen the pilotwalve is moved up to cause movement of the main valve tothe right said screw will be unscrewed from the nut 36 and thepilot-valverestored to normal or central position. The screw 37 and thepinion a0 can move axially to allow the pilot-valve to be moved from theoperatinglever 16, the pinion ell) being made wide-faced for thispurpose. lt will also be noted that by means of this arrangementwhatevermove ment is given to the pilotvalvc will be proportionatel y given tothe main valve and that this movement of the main valve restores thepilot-valve to central position. This forms a compact and eilicientpilot-valve mechanism.

The rod 38 extends out through a part rigidly secured to the casing,which has on its inner side a screw cam or helix 4:2 and on its outerface another screw am or helix 43. Rigidly secured to the rod 38 is ahelix :4, arranged to face the helix 42, and also a helix 4:5, arrangedto face the helix 43. These helices are formed to have the same pitch asthe screw 3'? and are set as shown in the drawings. It thus will be seenthat the rotating cams .4 and 45 are arranged to face each other andthat the stationary cams 42 and 43 are disposed between the same. Inpractice the high points of the cams are eased oil to correspond to thelap of the valves 24 and 26. This arrangement is usedv so as to preventa careless operator on the car violently reversing the motion of thecar.

As shown in the drawings the parts are in normal position and theoperator can move the pilot-valve either up or down from the centralposition any distance up to its extreme of travel, which lStllQ pitch ofsaid screw 37 or the distance said screw 37 will move when making onerevolution in nut 36. Suppose the operator should move the lever 16 halway down to the position shown at 4:6. This will move the pilot-valvehalt-way down and will cause the main valve to move half-way to theleft. This movement of the main valve will turn the pinion 40 ahalf-tufinwhich will restore the pilot-valve to normal position,thelever 16 remaining at position 4.6. This will bring the cams 4st and4C5 to the vertical position, shown in the drawings; but they haveturned halt-way around the distance that the cam is can now be movedinto caiii $2 or the distance the cam 45) can be moved into the cam aswill only be one-half of a pitch. The operator can now at any time movethe lever 16 still lower to increase the speed of tie can but fromposition as the operator can only move the lever 1b upward to thecentral position and cannot pass the central position until the highpoint of the cam 45 is turned back to clear the high point of the cam43,

which only takes place when the main valve reaches its closed positionin its travel to the right. Thus the operator cannot move theoperating-lever 16 up past the central position until the main valvereaches its closed or central position. If the operating-lever 16 shouldbe moved half-way up or to position -17, substantially the same actionwould take place, except that the cams l and 45 would be revolved ahalf-turn in the opposite direction when the main valve reaches itshalf-way position to the right to allow the cylinder B to exhaust,whereby the operating-lever 16 can only be moved back to the centralposition until the high point of the cam 44: is turned back past thehigh point of the cam as. The same action takes place no matter whatdegree the operating-lever is moved up or down, as the partialrevolution of the cams 44' and 45 is proportional to the movement of theo )QIELidD -lBVGZ 16-that is to say if the lever 16 is moved down to anyextent up to a full movement thereof it is locked from being moved backpast its central position by cams 45 and 4:23 until the main valve comesback to its central position, or if said lever i6 is moved upward to anyextent up to a full movement thereof it is locked from being moved backpast -its central position by cams 4A and 42' until the main valve comesback to its central position. This prevents a careless operator fromreversing the motion of the car violently or instantaneously, as themain valve must come back easily to its central position by reason ofthe graduated openings in the pilot-- valve, it being impossible tothrow the pilotvalve across the center to alter the gradual centering ofthe main valve. Each centering movement of the main valve takes place atexactly the same rate of speed as the main valve comes to rest as itmoves away from its central position to cause the car to go up and down.

While this construction is of use in any class of elevators employing apilot-valve, it is of particular advantage in hydraulic plunger-elevators, because if the motion of the car is violently reversedwhen going up the plunger is apt to bound in the cylinder or draw airinto the cylinder by reason of the momentum of the parts, while if thecar is violently reversed when descei'iding a water hammer or blow iscaused, which is apt to injure or derange the mechanism. These accidentsare avoided by the means described.

It will also be observed that the cams 'i" LU- nish a means forrestoring the pilot-valve to normal position after it has been shiftedto full limit of its travel. Fl/hen the pilot-valve is not thrown to itsfull limit of travel, the screw-threaded connection will serve torestore the pilot-valve to normal position; but when either set of camsis brought into engagement, which takes place when the lever 16 is movedto its extreme ,in either direction;

ion

the'cams will act to restore the pilot-valve to normal position.Further, if the screwthreaded connection should break or wear stop thecar on its downward run and the" left-hand valve to check and stop thecar on its upward run. The right-hand one of said valves is operatedfrom a weighted arm 48, which carries a sheave 49. A running rope isattached to the top ofthe car at 51, passes up over a sheave 52, downaround said sheave 49, over a sheave 58, and is secured to the car atMet practically the opposite side thereof relatively to 51. When the caris at the top of its run and starts downward, 51 will take up on therope 50and 54 will pay out the rope 50 practically at the same speed;but as the car approaches the lower end of its run 54 will not pay outthe rope 50 as fast as the same is'being taken up by 51,

owing to the accelerated increasing angular deflection of the rope'betweensheavc 53 and v 54. Hence the arm48 will be lifted at an iaccelerated speed,wl 1ereby the speed ofrthe' 1 car will be slowed downsome time before it 1 reaches the bottom of its run, hence insuring agradual and accurate stopping ofthe car i no matter what was itsdownward speed. The left-hand shut-off valve is actuated by a similarweighted arm 55, which carries sheave 56. Another running rope 57 isconnected to the bottom of the car at 58, passes down around sheave 56,up over a sheave 59, and then is attached to the car at at praciticallythe other side thereof relatively to 58. By this: arrangement as the'car.moves up- ;ward 58 will take up on the running-rope "57 and 60 willpay out said rope; but as the car reaches the uppermost limits of itstravel v ;the rope 57. will not be paid out between 60 and 59 as rapidlyas it is taken up by 58, owing to the accelerated increasing angularIdeflection of the rope between 60 and 59, and hence the arm 55 will beraised with an accelierating movement and the car gradually andaccurately brought to a state of rest at its :upper extreme of travel.These running controlling-ropes 50 and 57 are arranged so that they actonly as the car reaches the points where it is desired to slow down anddo not act to affect the intermediate full- ;speed movement in eitherdirection.

Referring now to the detail of the shut-off valves, the right-hand onewill be described: The arm48 is mounted onashaft which projects insidethe casing and carries an arm 61, which connects by link 62 to the valveproper, which consists of a double valve 63 and a ring-valve 64,'m0untedupon a hollow stem 65, the end of which is closed by acheck-valve 66,through which are bored small hoies 67. When the valve is moved to theleft, the double valve 63 will close the ports communicating with pipe21, and this movement can take place as fast as the rope 5O pulls up onthe sheave 49, as the check-valve 66 will open to permit the water toflow from the left-hand side of the valve 63 to the right-hand side.When the rope 50 slacks to permit the weighted arm 48 to descend, themovement of the valve to the right will beregulated by the size of theopenings 67. In ordinary operation the ring-valve 64 performs nofunction; but if vthe rope 50 should break the weighted arm 48 will movethe valve to an extreme position to the right,

'so that the ring-valve 64 will close the openings into pipe 21.

The small holes 67 make this movement an easy and gradual one andprevent an instantaneous shutoti' to cause a water-hammer. The left-handshut-off valve is constructed the same as that just described andoperates the same, except that it is arranged to operate when the carreaches the uppermost limits of its travel. It will be seen that whenthe'ri 'ht-hand shut-off valve moves to check and stop the exhaust fromthe elevator-cylinder, as shown in the drawings, the left-hand shut-offvalve still leaves full communication between pipe 20 and pipe 22. Hencealthoughthe car is gradually stopped as it-comes to its lowest extremeit is possible to start upward. from the lowest position at full speed.The sameaction takes place when the left-hand shut-off valve comes intooperation as the'carl reaches the uppermost part of its travel-that is,the right-hand shut-off valve leaves full communication between pipes 22and 21-so that it is possible to start down atlfull .speed. i Thedetails of the automatic shut-offvalve are'not claimed in thiscase, as

they are claimed in an application filed of even dateherewith, Serial No218,660; neither are the arrangements of running ropes which operate theshut-off valves claimed herein, as they are claimed in an applicationfiled July 5-, 1904, Serial No. 215,266.

In this application. for patent I do not intend to clairn,.broadly, anelevator-valve in which a rack-tnd-pinion connection forms part of theconnection for restoring the pilot valve and also permits a transversemovement of the pinion, as this subject-nutter is claimed in a priorapplication for patent on a pilot-valve. filed by me March 13, 1902,Serial No. 98,009; nor in this application for patent do I wish toclaim, broadly, the combination of a pilot-valve with means for limitingthe distance the pilot-valve may be moved at any one operation, as thissubject-matter is claimed, broadly, in an application for patent filedby me June 29, 1903, Serial No. 163,477. 1 intend in this presentapplication to claim IIC the improved details of the main valve andpilot-valve and the various mechanisi s arranged to control theoperation of the same I am aware that changes may be made in theconstruction of an elevator plant without departing from the scope ofthis invention as expressed in the claims and that certain featurescovered by the claims may be used in (ii ti'erent constructions and indiiierent combinations. 1 do not wish, therefore, to be limited to theconstruction I have herein shown and described; but

Vthatl do claim, and desire to secure by Letters Patent of the UnitedStates, is 1 1.. .ln an elevator valve mechanism, the combination of amain valve, a transversely-movable pilot-valve, a nut connected to beshifted from the elevator-car, a rod threaded into the nut and movablewith the pilotvalve, and a gear-and-rack connection between the rod andmain valve, said gear-and rack connection permitting an end wise travelof the rod so that the rotation of the rod will close the pilotvalvewhen the main valve has been shifted to desired position.

2. in an elevator valve mechanism, the combination of a main valve, apilot-valve, operating connections for the same, and means for limitingthe throw of the operating connections, comprising two facing camscarried by a rotating part, and stationary cams interposed between thefacing cams.

in an elevator valve mechanism, thecombination of a main valve, apilot-valve, connections for operating the pilot-valve from theelevator-car, a threaded connection operated by the travel of the mainvalve for restoring the pilot-valve to central position, and means forlimiting the throw oi the operating connections, comprising two facingcams carried by a rotating part, and two stationary cams interposedbetween the facing cams, said cams having the same pitch as the threadedconnection.

4. in an elevator valve mechanism, the combination of a main valve, apilot-valve, connections for operating the pilot-valve, means to restorethe pilot-valve to central position, means for preventing a reverse ofthe operating connections except when the main valve is in centralposition, and graduated openings in the pilot-valve for regulating themovement of the main valve.

5. In an elevator valve mechanism, the combination of a main valve, anda pilot-valve and easing therefor, said pi lot-valve casing having a setof ports constructed to throttle as the recess pilot-valve comes back toits central closed position and another port or passage controlling theflow, the pilot-valve being constructed and arranged to close saidpassage when the same is in central position and said passage beingarranged not to interfere with the-action of the set of ports when thepilot-valve is moved away from its central closed position.

6. In an elevator valve mechanism, a main valve, a pilot-valve,connections for operating the pilotvalve, connections from the mainvalve for restoring the pilot-valve to central position, openings in thepilot-val ve whereby the main valve will come easily back to centralposition, and means arranged to prevent areverse until the main valvecomes back to its central position.

7. In an elevator valve mechanism, a main valve, a pilot-valve,connections from themain valve for restoring the pilot-valve to centralposition, openings in the pilot-valve for slowing the movement of themain valve as it come back to central position from a travel in eitherdirection, and means arranged to prevent a reverse until the main valvecomes back to its central position.

8. A pilot-valve casing having two inlets, one connected to the pressureand the other to ope "ate the main valve and two outlets one connectedto the exhaust and the other to operate the main valve, a port orpassage between each inlet and outlet, valves 31 and 35 for controllingthe inlets and valves 32 and 34 for closing the ports between the inletsand outlets to prevent leakage when the pilot-valve is in centralposition.

9. A pilot-valve casing having two inlets, one connected to the pressureand the other to operate the main valve, bushings having ports throughwhich the inlets pass, two outlets from said casing one connected to theexhaust and the other to operate the main valve, port or passage betweeneach bushing and outlet, valves 31 and 35 working in said bushings, andvalves 32 and 3 for closing the ports between the bushings and outletsto prevent leakage when the pilot-valve is in central position .lntestimony whereof I have hereunto set my hand in the presenceoif twosubscribing. 3

witnesses.

THU'RE .LARSSOIT.

VJ itnesses:

LoUIs W. Son'rrnencrn, ANGIE M. Gopnsan.

